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Hey, I am new to this site. I just bought an 06' C50T and my fiance and I love it. I have previous experience with an 82' Kawasaki 750 and a 98' Honda Valkyrie (fathers).

I absolutely love everything about this bike except one thing, the highway cruising RPM's. I commute 124 miles a day and love using the bike for the fun factor and fuel mileage. Most of my commute is between 60-75MPH, which is in the 3700-4700 RPM range.

I have been considering different methods to lower cruising RPM's, specifically a taller rear tire/rim or different rear drive gears.

My specific requirements are a happy medium at highway speeds. Here are my opinions on what I may need to do this:

1)optimum efficiency is typically at max torque RPM, which in this case is 3500 RPM according to Suzuki.
2)I would like to run 65MPH (average of different cruising speeds/most highway speed limits) at 3500 RPM.

In order to accomplish this, I would need:

A)a 30" tire, compared to 26" stock tire. This is a 4" difference, which is unlikely to fit under the stock rear fender.

B)Final drive reduction of 3.00, rather than the stock 3.503.

Now my question's to all of you is this: Are you familiar with any company that manufactures different rear differential gears? Also, is there a different Suzuki (or other brand) gear that may fit the c50's rear diff housing that is closer to a 3:1 ratio.

If there is not a gear already manufactured, I may be in contact with a local high-performance manufacturing facility to see if they can manufacture a 3:1 rear drive gear.

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After some more research, I looked up the different gear ratios between the c50 and the c90. The c90 has a final drive ratio of 2.66:1, which would equal out to 3,082 RPMS at 65MPH on the c50.

I also looked up the online parts diagrams for the c50 and c90. According to the diagrams and part numbers, it appears as though the rear diff on both machines are quite similar. I may try get my hands on the c90's final driven gear and see if can be installed in the c50's case without modification.

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Second, unless you are a bonafide gearhead I wouldn't do that. Besides the hassle (unless you are a tinkerer) the bike needs that ratio for roll on power at cruising speed. Hook that tall gear to that 50 cubic in. motor and you'll be kicking it down a gear just to change lanes. The VL800 just is what it is, an 805cc bike. I personally think the Suzuki engineers got the most out of it with the OEM set up. And it don't hurt it to wind it up because it takes a lickin' and keeps on tickin'.

That said, if you are hell-bent on doing this I will be following your progress with much interest! Good luck!

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Going from a 3.503 final drive ratio to a 2.66:1, aren't you concerned your going to have to push it to get it rolling? The bottem end would really suck. I don't think the bike revs high at all at 65-70. That's it's sweet spot. It's 75 and on up that things get a little buzzy.
Viper

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Anyway, I am well aware of what it will do to acceleration and I personally don't mind switching gears... I love dropping a gear and hammering down.

472viper, I do believe it will be a little less responsive, but how much, who knows? I've done the "on paper" math, but that is much different that seat of the pants feel. Most of my riding is done on the highway or long country roads, so I am more concerned about that than buzzing around town.

Also, I would rather have a 3:1 rear drive than a 2.66, but if the 2.66 c90 fits without modification, that would be much easier than finding someone to manufacturer a 3:1.

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I think you will make 5th gear unuseable.
the bike already won't wind all the way out in 5th. If it would, you would be going 122mph when the rev limiter kicked in, which the bike will only do going wown a long steep hill.
You are deluding yourself about the "high revs" at 75mph indicated, the bike is just lazying along.

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My hats off to you for wanting to find a remedy to an issue that ALOT of people here complain about and that is the engine loosing its V-twin throb at highway speeds and developing a high RPM buzz instead. If you are willing to attempt it, I say go for it. Nay sayers never come up with cool ideas anyway. I for one would love for you to pursue this, I will keep track of your posts.

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Thanks for the encouragement fella's, I have read (and searched) quite a bit on this site for the last week. It is obvious that I am not the only one that believes this bike needs a taller gear. Judging by the posts, 9 out of the 11 posts are in favor (or interested) in a taller gear. I'd say that's a good reason to go for it.

meldooby, please don't think I am calling you out, however... If you have read my previous posts, you would have found that I do most of my riding above 60MPH (65-66 indicated). At these speeds I have noticed the floorboards, gas tank, both seats, and frame to be more buzzy than I would prefer. I also stated that I have previous experience with a 98' Honda Valkyrie that had absoluetely no buzz on the highway. Anyway, I'm an not interested in winding out my v-twin in fifth, that would be for someone who cruises the Boulevard (no pun intended) on a regular basis.

Also, as stated earlier, I would like a 3:1 rear drive rather than a 2.66, but at this point, the 2.66 is a more viable option... that is, until I start tearing the rear drive down. I also have a theory which is completely unproven, I would have to know the ring and pinion specs of the c50 and c90 to prove/disprove this theory:

The c50's final drive is 3.503, the c90's is 2.66. That is a difference of .837, divided by two (the average) is .419, which gives you a gear of 3.084... very close to 3:1 and darn near right at 3500RPM @65MPH, which is desired. Now the theory... does the c50 and c90 have different ring gears and different pinion gears, or are the pinion gears (on driveshaft) the same on both machines. "If" they are different and the c50 has a lower pinion gear, mated with the c90's taller ring gear, this may solve the problem entirely and produce a 3:1 ratio. Remember this is all speculation at this point, as I have not even looked at a set of gears for these bikes yet.

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Hey, I am new to this site. I just bought an 06' C50T and my fiance and I love it. I have previous experience with an 82' Kawasaki 750 and a 98' Honda Valkyrie (fathers).

I absolutely love everything about this bike except one thing, the highway cruising RPM's. I commute 124 miles a day and love using the bike for the fun factor and fuel mileage. Most of my commute is between 60-75MPH, which is in the 3700-4700 RPM range.

I have been considering different methods to lower cruising RPM's, specifically a taller rear tire/rim or different rear drive gears.

My specific requirements are a happy medium at highway speeds. Here are my opinions on what I may need to do this:

1)optimum efficiency is typically at max torque RPM, which in this case is 3500 RPM according to Suzuki.
2)I would like to run 65MPH (average of different cruising speeds/most highway speed limits) at 3500 RPM.

In order to accomplish this, I would need:

A)a 30" tire, compared to 26" stock tire. This is a 4" difference, which is unlikely to fit under the stock rear fender.

B)Final drive reduction of 3.00, rather than the stock 3.503.

Now my question's to all of you is this: Are you familiar with any company that manufactures different rear differential gears? Also, is there a different Suzuki (or other brand) gear that may fit the c50's rear diff housing that is closer to a 3:1 ratio.

If there is not a gear already manufactured, I may be in contact with a local high-performance manufacturing facility to see if they can manufacture a 3:1 rear drive gear.

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